Ashton said: “It’s clear ISIS deems its media operation to be as important as its military operation.”

ISIS propaganda is masterful, she says, at making people feel part of a romanticised brotherhood by combining images, music and filmmaking style which mimic western popular culture. But it goes far deeper than that – the filmmakers offer a new perspective on violence; they offer adventure, belonging and a utopian society in which the brotherhood thrives and sadism is allowed and legitimate in the name of a higher goal.

“No other terrorist group has come close to making young people feel prestigious and cool and that they hold a significant place in society.

“Terrorist recruiters are expert at manipulating terror so it becomes a seductive subculture, one that appears to be fashionable, cool and – critically – based on an understandable grievance.

“ISIS propaganda is designed to appeal to disaffected young men seeking excitement, glory, adventure, self-esteem and the possibility of becoming the ultimate badass. Alongside brotherhood, it promises a sense of purpose and solidarity. To cap it all, it is designed to appear to also offer spiritual redemption.”

The research strips back the veneer to reveal that ISIS uses five distinct narratives – seduction, grievance, warfare, theatrical violence, and illusion of utopia – which are the lifeblood of its recruitment strategy.

Rather than being the result of a single motivational process, the results show ISIS propaganda is a combination of social, cultural, political and religious appeals to seduce and recruit western youths. Propaganda plays a very large part in the radicalisation process, encompassing jihadism with feelings of excitement, adventure and existential superiority.

“The lie is you can be a badass and have exciting adventures, and the caliphate is sexy and powerful,” Ashton said.

“ISIS’s specialised media departments have produced a stream of jihadist propaganda combining a romanticised view of the Islamic State brotherhood and a direct invitation to ultra-violence.

Its videos and images feature a complex narrative directed at a number of audiences – potential recruits, existing fighters, sympathisers, antagonists – to offer a story of a triumphant, thriving caliphate with a just grievance, living in a utopian society with visceral camaraderie to all who want it, and the destruction of those who don’t.

Most of the videos are a seductive smorgasbord of enticing imagery, haunting music, choreographed action and extreme violence, Ashton said. Battle scenes are shot like Hollywood movies with slow moving cameras zooming in on the action as flames engulf the screen. Explosive battle scenes, in which specks of dust and ash are front and centre, and accompanied by ear-ringing sound effects, are designed to give the viewer a sense of being there.

Attractive males dressed in enticing military clothing, carrying powerful weapons, radiate the impression they are heroes and, after the battle, are filmed relaxing with friends in an illusion of a perfect society, of being part of a collective.

In some, films are shot to look like a first person shooter video game, to give the illusion the viewer is wielding the gun and is part of the action.

Others closely mimic the BBC programme ‘Casualty’ or the documentary ’24 Hours in A&E’ with fast-paced action and heart monitors flashing across the screen.

In ISIS videos of its soldiers murdering by execution, it’s as if the audience is encouraged to see how the executioners will surpass themselves this time, with an escalation in violence over the years, so each one is more extreme than previous killings.

“The brutality of ISIS execution videos indulges supporters, attracts fighters from abroad, and positions the group as powerful. These videos aren’t being produced just to secure support, the documented executions of enemy soldiers or spies is intended to intimidate opponents and polarise communities and provoke a reaction in the media, which helps spread their message further.”

ISIS fighters from the west are portrayed as particularly commendable for their loyalty to the cause, and films show them selected as fighters because they are superior, the chosen few, whereas the reality is western recruits are seen by ISIS as cannon fodder.

Rather than tell the story of a group of anarchists and social outcasts who want to destroy the world, the focus is on friendship, power and heroism to lure marginalised and disenfranchised youths.

Ashton said: The Islamic State is largely impenetrable – we know only what their propagandists want us to know. The results of this study have shown that alongside fighting, they are also expert storytellers, able to hijack the popular culture of the west and use it to seduce western youths.

“Visual images have a visceral and public impact that no other medium can match.

“The scenery, music, tone of voice, sense of power, the violence all ooze a seductive quality.

“They are experts at manipulating audiences into believing an idealised lie.”

Ashton watched 100 ISIS videos produced from 2015 to 2017.

A third were easily accessible via social media, and the majority were found as a result of searches and via ISIS online magazines.

“Ultimately,” she said, “their propaganda resembles a medieval reality show in which their own media is as much a part of the jihad as the jihad itself and its most effective recruitment tool is seductive savagery.”